Optimization of endoscopic ultrasound‐guided tissue sample acquisition for commercially available comprehensive genome profiling.

Background and Aim: Optimal tumor samples are crucial for successful analysis using commercially available comprehensive genomic profiling (CACGP). However, samples acquired by endoscopic ultrasound‐guided tissue acquisition (EUS‐TA) are occasionally insufficient, and no consensus on the optimal number of needle passes required for CACGP exists. This study aimed to explore the optimal number of needle passes required for EUS‐TA to procure an ideal sample fulfilling the prerequisite criteria of CACGPs. Methods: Patients who underwent EUS‐TA for solid masses between November 2019 and July 2021 were retrospectively studied. The correlation between the acquisition rate of an ideal sample and the number of needle passes mounted on a microscope slide was evaluated. Additionally, the factors predicting a successful analysis were investigated in patients scheduled for CACGP using EUS‐TA‐obtained samples during the same period. Results: EUS‐TAs using 22‐ and 19‐gauge (G) needles were performed in 336 and 57 patients, respectively. There was a positive correlation between the acquisition rate and the number of passes using a 22‐G needle (38.9%, 45.0%, 83.7%, and 100% for 1, 2, 3, and 4 passes, respectively), while no correlation was found with a 19‐G needle (84.2%, 83.3%, and 85.0% for 1, 2, and 3 passes, respectively). The analysis success rate in patients with scheduled CACGP was significantly higher with ideal samples than with suboptimal samples (94.1% vs 55.0%, P < 0.01). Conclusions: The optimal estimated number of needle passes was 4 and 1–2 for 22‐ and 19‐G needles, respectively. [ABSTRACT FROM AUTHOR]